Mixture adaptation method for internal combustion engines with direct gasoline injection

Abstract

A method for compensating for faulty adaptations of the pilot control of fuel metering for an internal combustion engine which is operated in the at least two different operating modes, homogeneous mode and stratified charge mode. The method includes mixture regulation and adaptation of mixture regulation occurring in homogeneous mode; switching occurring between the operating modes, depending on a desired operating mode which is determined from a plurality of operating mode requirements. Furthermore, each of the operating mode requirements are assigned a priority; and the desired operating mode is determined depending on the priorities of the operating mode requirements. Also, switching to homogeneous mode with the activation of the adaptation momentarily occurs, even outside the normal starting conditions of the adaptation. A deviation of the adaptation quantity from its neutral value during the short-time activation is evaluated as a suspected error, with the engine control program elevating the priority of the adaptation under normal starting conditions when a suspected error is present.

What is claimed is:  
     
       1. A method for compensating for faulty adaptations of the pilot control of fuel metering for an internal combustion engine operated in at least two different operating modes including a homogeneous mode and a stratified charge mode, comprising the steps of: 
       performing a mixture regulation and an adaptation of mixture regulation in the homogeneous mode;  
       switching between the operating modes depending on a desired operating mode determined from a plurality of operating mode requirements;  
       assigning a priority to each of the operating mode requirements;  
       determining the desired operating mode depending on the priorities of the operating mode requirements;  
       switching to the homogeneous mode with an activation of a temperature-dependent adaptation momentarily occurring even outside normal starting conditions of a range-dependent adaptation;  
       evaluating a deviation of a temperature-dependent adaptation quantity from a neutral value during a short-time activation as a suspected error; and  
       raising, by an engine control program, the priority of the adaptation under normal starting conditions when the suspected error is present.  
     
     
       2. The method according to  claim 1 , further comprising the step of activating the short-time mixture adaptation below a minimum temperature of the range-dependent adaptation. 
     
     
       3. The method according to  claim 2 , wherein the minimum temperature of the range-dependent adaptation is greater than or equal to 70° C. 
     
     
       4. The method according to  claim 1 , further comprising the step of activating the short-time mixture adaptation is activated for a period of time in the range of approximately 10 to 20 seconds. 
     
     
       5. The method according to  claim 1 , further comprising the step of canceling a physical priority if the error has been learned in a normal range-dependent mixture adaptation, so that the range-dependent mixture adaptation is enabled at normal priority by the engine control program. 
     
     
       6. The method according to  claim 1 , further comprising the steps of: 
       maintaining a value of the temperature-dependent short-time adaptation when a motor vehicle is parked; and  
       during an initialization phase, after a next time the engine is started, setting the value of the temperature-dependent short-time adaptation back by a value learned within the scope of a normal range-dependent mixture adaptation.  
     
     
       7. The method according to  claim 1 , wherein an operating parameter-dependent mixture adaptation includes at least one of a multiplicative and an additive effect on fuel metering. 
     
     
       8. The method according to  claim 1 , further comprising the step of renewing at least one value of the range-dependent adaptation above a temperature threshold, the at least one value having an effect on fuel metering independently of temperature. 
     
     
       9. The method according to  claim 1 , further comprising the step of deriving a deviation of a current temperature-dependent adaptation factor from a long-term adaptation factor to form the suspected error. 
     
     
       10. An electronic control device configured to perform a method for compensating for faulty adaptations of the pilot control of fuel metering for an internal combustion engine operated in at least two different operating modes including a homogeneous mode and a stratified charge mode, the method including the steps of: 
       performing a mixture regulation and an adaptation of mixture regulation in the homogeneous mode;  
       switching between the operating modes depending on a desired operating mode determined from a plurality of operating mode requirements;  
       assigning a priority to each of the operating mode requirements;  
       determining the desired operating mode depending on the priorities of the operating mode requirements;  
       switching to the homogeneous mode with an activation of a temperature-dependent adaptation momentarily occurring even outside normal starting conditions of a range-dependent adaptation;  
       evaluating a deviation of a temperature-dependent adaptation quantity from a neutral value during a short-time activation as a suspected error; and  
       raising, by an engine control program, the priority of the adaptation under normal starting conditions when the suspected error is present.  
     
     
       11. The device according to  claim 10 , wherein the method further includes the step of activating the short-time mixture adaptation below a minimum temperature of the range-dependent adaptation. 
     
     
       12. The device according to  claim 11 , wherein the minimum temperature of the range-dependent adaptation is greater than or equal to 70° C. 
     
     
       13. The device according to  claim 10 , wherein the method further includes the step of activating the short-time mixture adaptation is activated for a period of time in the range of approximately 10 to 20 seconds. 
     
     
       14. The device according to  claim 10 , wherein the method further includes the step of canceling a physical priority if the error has been learned in a normal range-dependent mixture adaptation, so that the range-dependent mixture adaptation is enabled at normal priority by the engine control program. 
     
     
       15. The device according to  claim 10 , wherein the method further includes the steps of: 
       maintaining a value of the temperature-dependent short-time adaptation when a motor vehicle is parked; and  
       during an initialization phase, after a next time the engine is started, setting the value of the temperature-dependent short-time adaptation back by a value learned within the scope of a normal range-dependent mixture adaptation.  
     
     
       16. The device according to  claim 10 , wherein an operating parameter-dependent mixture adaptation includes at least one of a multiplicative and an additive effect on fuel metering. 
     
     
       17. The device according to  claim 10 , wherein the method further includes the step of renewing at least one value of the range-dependent adaptation above a temperature threshold, the at least one value having an effect on fuel metering independently of temperature. 
     
     
       18. The device according to  claim 10 , wherein the method further includes the step of deriving a deviation of a current temperature-dependent adaptation factor from a long-term adaptation factor to form the suspected error.